End fastener for eyeglass holders

ABSTRACT

An improved end fastener for attaching the end of an eyeglass-holder cord to a temple leg of eyeglasses includes an elongated elastomeric body having a double-tapered slot for resiliently mounting the body about a temple leg. The slot has a slotted narrow web at the narrowest location. A hole in the body holds a connector ring to connect the body to an end of the holder cord via an eyelet of a cord-end cap. Molding of the double-tapered slot includes use of two opposed, tapered cores, each disposed in a half-cavity of the mold.

This application is a divisional of U.S. patent application Ser. No.593,436, filed on Jan. 29 1996, now issued as U.S. Pat. No. 5,655,264,on Aug. 12, 1997.

This invention relates to an end fastener for eyeglass holders and, moreparticularly, to an improved end fastener for attaching the end of aholder cord to a temple leg of an eyeglasses frame.

Eyeglass holders formed by a cord whose ends are attached to the templelegs of the glasses by an end fastener are known and utilized in theprior art. Conventionally, such end fasteners are affixed to the ends ofa holder cord and comprise a loop or eyelet of elastic material and/ormetalic spring components to resiliently grip eyeglass temple legs uponmounting thereto.

Various eyeglass holder devices are disclosed in prior art. Forinstance, U.S. Pat. No. 5,092,668 to Welch shows a number of features ofeyeglass cord retainer apparatus. Many of these features are present indevices available in the marketplace. The Welch '668 patent discloses asecurement cord with a ring formed at each end, whereby each ring ismounted to an elastomeric loop. Each elastomeric loop includes a medialspring member encompassing each loop to effect an upper and lower loopwith the upper loop of each elastomeric loop resiliently securing atemple leg of an eyeglass assembly. (see FIG. 3). Typical examples ofart prior to Welch et al are shown in FIGS. 1 and 2.

Sugarman (U.S. Pat. No. 4,965,913) discloses a strap for glasses. Thestrap includes at each end a loop 24 for holding a temple bar 12,14.

Seet (U.S. Pat. No. 4,820,036) discloses a headband for retention ofglasses. The headband has a connector end 20 that includes a slit ornarrow opening 22 which may be surrounded by an enlarged recessed area23. Connector end 20 is pushed over a temple leg to attach the headbandto the glasses.

Seron (U.S. Pat. No. 4,136,934) discloses an eyeglass holder comprisingan elongated strap 14. Ends 18 of strap 14 mount temple receiving andholding fixtures 20. Fixtures 20 include a tail-like projection 24 thatincludes an elongated slot 26 for receipt of a temple 12, 14.

Other prior art patents that include aspects of relevance to the presentinvention are: U.S. Pat. No. 3,979,795 (Seron); U.S. Pat. No. 2,780,853(Guthman); and, U.S. Design Pat. No. 185,852 (McFadyen).

Conventional eyeglass holders or retainers are known to exhibit someundesirable and disadvantageous properties. Such undesirable attributescan be related to functional deficiencies and/or to manufacturingaspects. In regard to the latter, for instance, need for specialmachinery and fixturing, high labor content and/or high material cost,etc. are generally representative of disadvantageous characteristics.

Some of the prior art eyeglass holders of versions that are commonlyavailable in the market are akin to those shown and disclosed by theWelch '668 patent. Such devices have a number of disadvantages. Loopsfor holding temple legs tend to lose elasticity and can thusly allowdetachment of the holder cord from the temple leg. Rings, springs,adjustable collars, etc. which serve for adjustment to temple-leg sizeand to hold tension of the loop over the temple leg have often beenfound inadequate to the task; and, moreover, have added material andlabor cost. They also frequently capture and pull the user's hair.

Some prior art devices, particularly those having cord-end fastenersmolded in one piece or fused with ends or extension components of thecord, drastically limit the choice of cord material to only those thatare not adversely affected by high-temperature molding or fusingconditions. Thus, for instance, it is difficult to fuse or heat sealleather cord effectively suitable moldable elastomeric materials; and,cords of Nylon and similar plastics are apt to melt at fusingtemperatures. Additionally, rigid joining of end fasteners to cords (byfusing and otherwise) requires a relatively bulky joint region, which isundesirable both for reasons of the user's inconvenience and of materialand cost.

A persistent problem associated with many, if not most conventionaleyeglass holders lies with the unreliable holding capability of cord-endfasteners about eyeglass temple legs, particularly since temple legs ofdifferent types of glasses significantly differ in size and shape.Although various solutions have been disclosed, many have been found tobe either ineffective in the long run or costly--particularly when usedin combination with other features. For example, Guthman (U.S. Pat. No.2,780,853) discloses a metal spring clasp for attaching ends of a cordto eyeglass temples. This appears to be effective, but it is also arelatively high-cost solution. One-piece, molded cord-end fasteners ofelastomeric material go a long way toward low cost, but they often poseproblems with unadaptability to different temple sizes and withunreliability of attachment. In this respect, Seet (U.S. Pat. No.4,820,036) shows an end member 20 (molded in one piece with theheadband) having an opening 22 through which is passed a temple leg thatis to be held securely. Whereas the end member requires relatively highresiliency and elasticity to accommodate and reliably holddifferent-size temple legs, the headband needs substantially lessresiliency and elasticity to be effective in use.

Another solution to the need for reliable holding to different sizetemples is disclosed by Seron (U.S. Pat. No. 4,136,934) wherein aholding fixture 20 at the end of a band 14 includes a tail-likeprojection 24 with an elongated slot 26 for receipt of one of thetemples. In order to provide tight gripping for differing size temples,a projection 24 is provided with a wire band 34 whose position isadjustable along projection 24 to close the slot. Again, however,adjustable collars or wire bands, etc. have often been found inadequateto the task. Moreover, they require added material and labor cost, whilefrequently capturing and pulling hair.

Accordingly, it is a feature of the present invention to provide apractical and functionally convenient and effective end fastener foreyeglass holders that is reliable, cost-effective, attractive, andconvenient in use.

SUMMARY

In accordance with principles of the present invention, there isprovided an improved end fastener for attaching the end of a holder cordto a temple leg of eyeglasses. The improved end fastener is effective,attractive, convenient to use, reliable, and relatively low in cost.

The improved end fastener of the invention includes an elongated,molded, elastomeric body for resiliently mounting the fastener about atemple leg of eyeglasses. The fastener further includes a connector-ringholder for connecting the body to an end of the cord of an eyeglassholder via a cord-end cap.

The cord-end cap comprises a substantially cylindrical tube that ishollow with one end closed--the outside of the closed end being providedwith an eyelet for connecting to the connector ring. The inside of thecap serves to secure an end of the cord thereto by crimping of the capabout a cord-end, by adhesive attachment of the cord-end within the cap,by fusing of the cord-end material to the inside of the cap, or bysimilar processes. A connector ring holder is formed by a hole throughthe end-fastener body.

A means for resiliently mounting the body about a temple leg includes anelongated slot extending through the body. The width of the slotdecreases with depth to the middle of the body and, thereafter, againincreases symmetrically toward the other side of the body. Thisdouble-tapered shape of the slot is achieved during molding of the bodyby use of two tapered, spade-like cores that protrude from the bottom ofthe mold cavity, one from each mold-half. Mold and cores are assembledso that the cores become components of the mold.

In a preferred embodiment, the slot includes a narrow web of material(having a slot-shaped opening) located in the middle of the body. Thisis achieved by provision of an appropriate step along the edge of thetip of one or both core pins. The lips formed by the web extendlaterally into the slot. They are operative and particularly effectivein capturing, pinching, and securely engaging temple legs that arerelatively small in cross-section, but flexible enough to accommodatethicker temple legs.

The elongated and symmetrically tapered slot facilitates convenientinsertion of temple legs from either side into and through theend-fastener body and provides secure engagement and attachment fortemple legs of differing sizes.

A preferred method for manufacturing the elastomeric end-fastener body,in particular the elongated, double-tapered slot therein, is to mold thebody in a mold of two similar half cavities, each half cavity includinga tapered core that extends from wall across the half cavity. In thismanner, the tips or apices of the cores meet (at the narrowest end ofthe tapers) when the half cavities are closed upon one another along anabutment plane. The half cavities thusly form the mold cavity ready forinjection of the heated and pressurized elastomeric material. Once theelastomeric material is injected and appropriately cooled andsolidified, the half cavities are drawn apart substantially along thedirection of the tapered cores so that the cores withdraw from thenow-molded body. The molded body can then be taken from the mold bypulling it off the tapered cores.

The assembly procedure of an eyeglass holder according to the inventionincludes attaching each cord-end of the eyeglass holder cord within thehollow tube end of the cord-end cap and connecting the cord-end cap tothe end fastener body by means of the (open) connector ring (jump ring)that is threaded through the end cap's eyelet and through the connectorhole in the end-fastener body. The connector ring is subsequently bentto a closed shape.

For use, the assembled eyeglass holder is attached to eyeglasses bypushing each end-fastener body (at each end of the assembly) with itselongated slot over one of the two temple legs of the eyeglasses into anappropriate position along the temple legs.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference numerals refer to likeparts throughout different views. The drawings are schematic and notnecessarily to scale, emphasis instead being placed upon illustratingprinciples of the invention.

FIG. 1 is perspective illustration of an embodiment of the deviceaccording to principles of this invention, the device being shownassembled and attached to eyeglasses;

FIG. 2 is an enlarged schematic plan view of the device shown in FIG. 1;

FIG. 3 is an enlarged schematic side view of the device shown in FIG. 2;

FIG. 4 is a schematic sectional view of the device shown in FIG. 3,taken along section lines 4--4;

FIG. 5 is a schematic fragmental sectional view of a mold portion thatrelates to the part depicted in FIG. 4;

FIG. 6 is an enlarged schematic sectional view of the device in anotherembodiment;

FIG. 7 is an enlarged schematic fragmental sectional view of a portionof a mold for providing the embodiment shown in FIG. 6; and,

FIG. 8 is an enlarged schematic fragmental sectional view of a portionof a variation of a mold for providing the embodiment shown in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1 of the drawings, there is depicted an eyeglassholder 10 including end fasteners 12 according to the invention. Holder10 is shown attached to temple legs 16 of eyeglasses 14. Each of thetemple legs 16 is inserted through and securely mounted in one of theend fasteners 12.

Eyeglass holder 10 further comprises a holder cord 18 having ends 20,cord-end caps 22, and connecting rings 24. Ends 20 are inserted intocord-end caps 22. Each cord-end cap 22 includes an eyelet 26. Aconnecting ring 24 couples each end fastener 12 to an eyelet 26 of acord-end cap 22. End fasteners 12 are thusly joined and connected to theholder cord 18. Other alternate component arrangements can be used toconnect between ends 20 and connecting ring 24 while utilizing the endfastener embodiments of the present invention.

Referring now to FIGS. 2-4, there is depicted an embodiment of the endfastener 12 in various orthogonal views. End fastener 12 comprises abody 30 of an elastomeric material that has an elongated generallyobovoid shape that includes a narrow base 32 and a broad end 34. A longaxis 36 is defined through centers of base 32 and end 34.

Means for securely mounting end fastener 12 resiliently over temple leg16 is comprised in body 30 and includes a slot 38 that extends throughbody 30 substantially orthogonally to axis 36. Slot 38 is elongated inthe direction of axis 36. As particularly apparent from FIG. 4, slot 38has a breadth that tapers from opposite outsides of body 30 toward themiddle thereof; i.e. toward the region of axis 36. This double-taperedslot 38 is operational in receiving temple leg 16 and securely holdingit by virtue of the elasticity and resiliency of body 30. Thedouble-taper shape of slot 38 facilitates easy introduction of a templeleg 16 from either side of the slot and accommodates differingcross-sectional sizes of temple legs.

Means for connecting body 30 to the end of a holder cord 18 includes ahole 39 laterally through the body at narrow base 32. As indicated inconjunction with the illustration of FIG. 1, a connecting ring 24 isemployed to connect end fastener 12 (body 30) to holder cord 18 viacord-end cap 22. In assembly, connecting ring 24 is threaded throughhole 39 (also through eyelet 26 of end cap 22) and is thereafter bentclosed in the manner of "jump rings" in jewelry manufacture.

It should be understood that the slot 38 and particularly the taperthereof and the resulting constriction in the region of the axis 36 ofthe resiliently elastic body 30 are operative in nipping, squeezing, andpinching a temple leg threaded through the slot 38 to effect secureholding and retention.

Referring particularly to FIGS. 2 and 3, it can be seen that narrow base32 has a lateral breadth that is less than the breadth in acorresponding lateral direction of broad end 34.

Referring now to FIG. 5, there is depicted a fragmental sectional viewof a portion of a mold 40 for molding slot 38 (FIGS. 2-4). The view ofFIG. 5 (mold 40) relates to the view of FIG. 4 (body 30 and slot 38).Mold 40 comprises two half cavities 42,42' and, extending from theinsides of the cavities, tapered spade-like cores 44, 44' which bridgeacross the cavities so that apices 45, 45' of cores 44,44' abut. The twomold halves with half cavities 42,42' are shown mated along abutmentplain 46 to form the closed mold cavity in preparation for the moldingprocess.

Referring now to FIG. 6, there is depicted a sectional view of anotherembodiment of the invention. Shown here is an end fastener 52 that issimilar to end fastener 12 shown in the view of FIG. 4, except that thebody 54 of end fastener 52 has a slot 56 that includes lips 58. Lips 58extend laterally from the sides of slot 56 in a substantially centralregion of body 54.

The slot 58 and particularly the taper thereof and the constrictioneffected by the lips 58 in the middle region of the resiliently elasticbody 54 are operative in nipping, squeezing, and pinching a temple legthreaded through the slot 56 to effect secure holding and retention.

End fastener 52 is equally as effective in securely holding temple legsof wide cross-sections as it is in securely holding temple legs ofnarrow cross-sections. In this respect, the ability to accommodate alarge range of sizes of temple legs is especially enhanced by theprovision of lips 58. The addition of lips 58 broadens the accommodationrange for differing temple-leg sizes toward those having narrowercross-sections while not curtailing the ability to securely hold largetemple-leg sizes.

In respect to structure not specifically shown in FIG. 6, end fastener52 is substantially identical to the embodiment illustrated in FIGS. 1-3and described in conjunction therewith.

Referring now to FIG. 7, there is shown a fragmental sectional view of aportion of a mold 60 for molding slot 56 shown in FIG. 6. Mold 60comprises two half cavities 62,62' and, extending from the insides ofthe cavities, tapered spade-like cores 64, 64' which bridge across thecavities so that apices 65,65' abut. The two mold halves with halfcavities 62,62' are shown mated along abutment plain 66 to form theclosed mold cavity in preparation for the molding process. Tapered cores64, 64' include steps 68,68', respectively, for forming of lips 58 (FIG.6).

Referring now to FIG. 8, there is shown a fragmental sectional view of aportion of an alternate mold 70 for molding slot 56 shown in FIG. 6.Mold 70 comprises two half cavities 72,72' and, extending from theinsides of the cavities, tapered spade-like cores 74, 74' which bridgeacross the cavities. Apices 75,75' abut. The two mold halves with halfcavities 72,72' are shown mated along abutment plain 76 to form theclosed mold cavity in preparation for the molding process. In thisalternate mold version, only one of the tapered cores, namely taperedcore 74' includes steps 78 for forming of lips 58 (FIG. 6).

A preferred method for manufacturing the elastomeric end fastener body,in particular the elongated, double-tapered slot, is to mold the body ina mold of two similar half cavities, as described in the foregoing. Eachhalf cavity includes a tapered core that extends from the wall acrossthe half cavity, whereby the tips of the cores meet (at the narrowestend of the tapers) when the half cavities are closed upon one another.The half cavities thusly form the mold cavity ready for injection of theheated and pressurized elastomeric material. Once the elastomericmaterial is injected and appropriately cooled and solidified, the halfcavities are drawn apart substantially along the direction of thetapered cores so that the cores withdraw from the now-molded body. Themolded body can then be taken from the mold by pulling it off thetapered cores.

In one embodiment, the double-tapered slot includes a narrow web ofmaterial (having a slot-shaped opening) located in the middle of thebody. As hereinbefore described, this is achieved by provision of anappropriate step along the edge of the tip of one or both cores. Thelips 58 formed by the web extend laterally into the slot and are formedduring molding of body 54 from the same elastomeric material.

In an embodiment of the invention, molding of the end fastener ispreferably effected with elastomeric material having an "A" Shorehardness in the range of 30 to 62, a specific gravity in the range of0.89 to 1.0, and a tensile strength between 750 and 1,200 psi. Moldingis preferably effected at a molding material temperature between 325 and400 degrees F while the mold itself is heated to run in the range of 60to 110 degrees F. Many conventional silicon elastomers are acceptablefor use in the molding of the end fasteners. Alternatively, acommercially available moldable elastomer known as Krayton can beadvantageously used for molding the end fastener.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes and modifications in formand details may be made therein without departing from the spirit andscope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. An end fastener forattaching an end of an eyeglass holder cord to a temple leg of a pair ofeyeglasses, the end fastener comprising:a body of a resilient material,said body having an elongated shape including a base with a center andan end, and further having a long axis defined through the center ofsaid base and said end, said body including means adapted for mountingsaid body resiliently on a temple leg, said means for mountingcomprising a slot extending completely through said body in a lateraldirection substantially orthogonal to said axis, said slot beingelongated in the direction of said axis; and, means for connecting saidbody at said base to said end of a holder cord, said means forconnecting comprising a hole extending through said body in the samedirection as said slot, substantially orthogonal to said axis around aregion of said base;said slot being adapted to securely hold a templeleg threaded therethrough by force exerted due to the resilient natureof the body.
 2. The end fastener according to claim 1, wherein saidmeans for mounting further includes means adapted for pinching a templeleg, said means for pinching being located in said slot in a vicinity ofsaid axis inside thereof.
 3. The end fastener of claim 2, wherein saidmeans for pinching includes lips extending laterally into said slot. 4.The end fastener according to claim 1, wherein said base has an extentin any lateral direction that is less than the extent of said end in acorresponding lateral direction.
 5. The end fastener according to claim1, wherein said body is molded of an elastomeric material, said materialhaving an "A" Shore hardness in the range of about 30 to 62, a specificgravity in the range of about 0.89 to 1.0, and a tensile strengthbetween about 750 and 1,200 psi.
 6. The end fastener according to claim1, wherein said body is molded of a silicon elastomer.
 7. The endfastener according to claim 1, wherein said elongated body is of agenerally obovoid shape and wherein said base is more narrow than saidend.
 8. The end fastener of claim 1, wherein said means for connectingfurther comprises a jump ring that is threaded through said hole.
 9. Theend fastener of claim 8, wherein said means for connecting includes acord-end cap that fits over and about said end of a holder cord and isattachable thereto, said cord-end cap including an eyelet for engagingsaid jump ring.
 10. The end fastener of claim 8, further comprisingmeans for coupling said jump ring to said holder cord.
 11. The endfastener of claim 1, wherein said body is molded of an elastomericmaterial.
 12. The end fastener of claim 1, wherein the means forconnecting comprises a hole which is separated from said slot by solidelastomeric material.
 13. The end fastener of claim 1, wherein the slotand the hole are present in a unitary body of elastomer and are not incommunication with each other.